Crystal Clear Aquatics AAD00322 Coralline Advanced Aquaculture Reef Epoxy Stick, 2-Ounce, Purple Advanced aquaculture reef epoxy is specially designed to secure rock work, coral colonies or other Epoxy will cure both in or out of water to a purple color that closely resembles coralline algae Reef epoxy will have no affect on your protein skimmer This product contents 2-ounces reef